Stuck at rest stop with stuck parking brake. Need advice.
Is your air building up above 65psi?
Roland
Yes
Does the brake knob stay pushed in when you try to release the parking brake.
Roland
It finally released. It does stay pushed in. Have tested several times, now seems to be working.
Air pressure steady at 115 and 120.
I was checking some diagrams may have had a stuck valve or one going bad. Glad you got it released.
Roland
Do you think I should abort trip? Only 60 miles from home.
Cycled it 15 times successfully
I would go with it.
Roland
Think I would continue the trip. Refresh in your mind how to disable the parking brake springs and be sure you have the tool to release them in case it decides to set to park again going down the road.
Be sure to chock the coach if you have to get under there to release them.
Best to be hooked to a tow truck before you cage the brakes...
D2 valve is oil fouled. Mine did the same thing.
Replaced. Raised the D2 to 110/130. Better brakes
Made it to first campsite. Anybody point me to link how I could release parking brake if stuck. Still a newbie. I've got chocks and safety supports for frame with me and some tools. Thanks for the quick reply to my post. Much appreciated.
Physically back off the spring chambers. But then zero parking brake. Fix the D2 valve imo,
It took me pulsing the brake pedal until near zero pressure to have the stuck valve open and build pressure.
You are at the beginning of that bad of a failure I think..
You have time to find a shop and replace the valve. Get the higher pressure one
Okay thanks.
Don't mess with the highly loaded spring parking or emergency brake cylinders, can kill you if you don't know what you are doing.
With air pressure like this, not sure we have any indication that the D2 (air compressor governor) is at fault.
Low air pressure, absolutely look at the D2. And the parking/emergency brake is set up to NOT release with low air pressure.
Here is a you tube link on how to cage brakes.https://m.youtube.com/watch?v=dwmt3zuRoYA
Hope you get to your destination with no further issues.
Roland
I've had the issue before on my truck. It was the relay valve sticking. When it wasn't releasing did the handle stay in at that time? If not the dash valve was the culprit. I have had to replace them but not for failing to release brakes.
The dash valve didn't feel right when it was stuck. It didn't feel like it was pushing in cleanly like it normally does.
They are simple and inexpensive.
In your travels stop at a Napa store and tell them you need a Haldex 20021 dash parking brake release valve.
I had the DD3 parking brake chamber stick on my 4107 bus right in the middle of the road in Rocky Mountain National Park. I stopped so the kids could take a close look at a couple of marmots. I spend about 20 minutes trying to release it, built air, tried again and again. Lots of cars behind me by that time. Finally, it released and away we went. Never stuck again and I pulled it apart and rebuilt it at home. Was really nasty inside. How easy it is to take releasing the brakes for granted. How paranoid you can be after it happens if along way from home.
Pierce
Will be stopping at Napa.
Bump...
I was on my way to get fuel.. at the end of the driveway. Parking break won't release..
What is your air pressure, if low that's the problem.
100
Yes, 100 psi that's OK, they should release, so not the air pressure.
Knob goes in and out... but it doesn't release.
Parked it... no diesel for now.
can you back up a foot?
Tim Fiedler
Sure Start Soft Start (http://www.gen-pro.biz)
TCER Direct (http://www.tcerdirect.com) generator-gas-prod (http://www.generatorgasproducts.com) 630 240-9139
Gen-Pro
Do you have a helper who can (carefully) watch the L and R rear calipers to see if both are moving, or 1, or none move when you push in the dash parking brake knob. Does the knob stay in when pushed in?
I think it's related to my dead batteries. Backed up, turned the coach off, released the brake at it rolled.. set brake. Tried to start and nothing. It had been running for 30 minutes. Reading 10 amps. Still doesn't have juice to start.
My 3208 cat belts that drive the air compressor also drive the alternator check if they are slipping yours may be different. May want to run a high idle as I was thinking 6V92 excessive idle time is not good.
I didn't intend to idle it that long.. but between searching the phone, trying to get the brake to release... that's what happenend. The belts are old, but not slipping.
It released when the engine was off, but it sure felt like it was on with the engine running (and the light was on).
I know I am in over my head, know nothing about rvs, diesels, or foretravels.. but I have to sell the house. I have to figure it out fast.
The air compressor is direct drive, no belts. Build pressure to 110 psi and repeatedly try to release parking brake.
Pierce
Air pressure stopped at 100.. can I tell it to build more? It was dumping air at 100..
Do it at 100.
Yep.. did. Based on what the thread said.. didn't seem to be working so I parked it. Trickle charge so it starts more than once and will try again.
Lift the dash and check the back of the valve if you can reach it. Next stick your head under the wheels with the switch off, wife on the brakes hard , and listen for hissing coming from any chambers. They bolt together. The book says to never unbolt the spring side of the chamber but air releases them . "Tap lightly with spanner" come to mind ..
Does this year have disc?
Yes disc, no wife... but have a great northwest farm terrier (border collie /airdale mix). She gets car sick though.
The tips are much appreciated. Will try anything
Do you have a cage bolt? Maybe you can cage one side and then the other to free it up. Maybe the calipers are stuck?
No hissing?
Hissing when the engine is on and the step is retracted.. not sure about from the brakes. No hissing when the brake is on and step is down.
How many minutes between dumps? May just be the $15 D2 valve, which you sometimes tap on to free up, or just replace. Walk into a truck parts supply shop and tell them you need a D2, the guy at the counter reached down, grabbed one, and asked if I needed anything else. New D2 goes off at 130 psi so I have some additional reserve capacity, and can add air to the tires faster. Got a rebuilt air dryer while I was there cause mine was overdue for total service. $180 - $90 core charge. Air system is happy now.
Follow the hiss to it's source. Could be the step if it is air powered.
Sitting there with the engine off air pressure gauge at 100 PSI push in the emergency brake valve what does the air gauge do? Drop a little or continue to drop?
Engine off it dropped 20 psi before I pulled it out again.. engine on it didn't change.
Just dropped 20 and settled there for a few minutes with the engine off?
You need more than a trickle charger to bring the three engine batteries up. You need to find a trucker to bring you up to speed on all your systems. You are on shaky ground now. You got a deal on the coach, sell your house for what it will bring so you get out of the situation you are in. I only wish you the best.
Pierce
I was mostly watching sideways on a gentle grade to see if it was rolling... it was. Not sure if the needle was still falling.
Ty Pierce... learning as fast as I can and yes, I can fix it.. as soon as I figure out what to fix.
Call it a midlife redo. With a smaller than retirement budget.
Parking/emergency rear brakes are spring loaded so that it is fully engaged with no air pressure or once the pressure falls too low (fail safe) should you lose all air pressure the rear brakes will attempt to drag you to a halt. So adequate pressure is required to release them. Pressure gauges are typically +/- 3-5% accurate of their TOTAL range. Do the math and you will realize the limitations. Just cause the coach won't move until you start the Engine and air pressure builds and then it can roll is a dangerous situation.
Are you holding the valve in for a few seconds before releasing it? Sometimes it takes time to hold the valve in.
Still no luck. There is some play in the parking brake know.. the piece benind the dash rotates a bit.
Ok. The brake is releasing, but the dash light stays on.. so I got diesel. Little unnerving driving with the light on. Will have to fix that.
The light is controlled by a pressure switch on the park brake release valve behind the dash
Paul,
If you decide to do any work on the parking brake control valve, here is a thread on my rebuild. Might have some helpful info.
Bendix PP-1 Repair Kit (http://www.foreforums.com/index.php?topic=27892)